1. Field of the Invention
This invention relates to apparatus employing a microwave radiometer to measure the temperature of a specimen and, more particularly, to improvements in such apparatus.
2. Description of the Prior Art
Apparatus employing a microwave radiometer to measure the temperature of a specimen has been known in the art for some time and, by way of example, is used medically to measure the subsurface body tissue temperature of a patient. In this regard, reference is made to the article "Microwave Radiometers for Non-invasive Measurements of Subsurface Tissue Temperatures", by F. Sterzer, which appears in the publication Automedica, 1987, Vol. 8, pages 203-211. Reference is also made to the article "Microwave Radiometric System for Biomedical `True Temperature` and Emissivity Measurements", by K. M. Ludeke and J. Kohler, which appears in the publication Journal of Microwave Power, 18(3), 1983, pages 277-283.
More recently, several improvements in apparatus employing a microwave radiometer to measure the temperature of a specimen have been made, which improvements are disclosed in U.S. Pat. No. 5,149,198, that issued Sep. 22, 1992 and is assigned to the same assignee as the present invention. The disclosure of U.S. Pat. No. 5,149,198 is incorporated herein by reference.
The present invention is directed to additional improvements in apparatus employing a microwave radiometer to measure the temperature of a specimen, including improvements to the microwave radiometer itself.